/* via-rhine.c: A Linux Ethernet device driver for VIA Rhine family chips. */
/*
Written 1998-2001 by Donald Becker.
Current Maintainer: Roger Luethi <rl@hellgate.ch>
This software may be used and distributed according to the terms of
the GNU General Public License (GPL), incorporated herein by reference.
Drivers based on or derived from this code fall under the GPL and must
retain the authorship, copyright and license notice. This file is not
a complete program and may only be used when the entire operating
system is licensed under the GPL.
This driver is designed for the VIA VT86C100A Rhine-I.
It also works with the Rhine-II (6102) and Rhine-III (6105/6105L/6105LOM
and management NIC 6105M).
The author may be reached as becker@scyld.com, or C/O
Scyld Computing Corporation
410 Severn Ave., Suite 210
Annapolis MD 21403
This driver contains some changes from the original Donald Becker
version. He may or may not be interested in bug reports on this
code. You can find his versions at:
http://www.scyld.com/network/via-rhine.html
[link no longer provides useful info -jgarzik]
*/
#define DRV_NAME "via-rhine"
#define DRV_VERSION "1.4.3"
#define DRV_RELDATE "2007-03-06"
/* A few user-configurable values.
These may be modified when a driver module is loaded. */
static int debug = 1; /* 1 normal messages, 0 quiet .. 7 verbose. */
static int max_interrupt_work = 20;
/* Set the copy breakpoint for the copy-only-tiny-frames scheme.
Setting to > 1518 effectively disables this feature. */
#if defined(__alpha__) || defined(__arm__) || defined(__hppa__) \
|| defined(CONFIG_SPARC) || defined(__ia64__) \
|| defined(__sh__) || defined(__mips__)
static int rx_copybreak = 1518;
#else
static int rx_copybreak;
#endif
/* Work-around for broken BIOSes: they are unable to get the chip back out of
power state D3 so PXE booting fails. bootparam(7): via-rhine.avoid_D3=1 */
static int avoid_D3;
/*
* In case you are looking for 'options[]' or 'full_duplex[]', they
* are gone. Use ethtool(8) instead.
*/
/* Maximum number of multicast addresses to filter (vs. rx-all-multicast).
The Rhine has a 64 element 8390-like hash table. */
static const int multicast_filter_limit = 32;
/* Operational parameters that are set at compile time. */
/* Keep the ring sizes a power of two for compile efficiency.
The compiler will convert <unsigned>'%'<2^N> into a bit mask.
Making the Tx ring too large decreases the effectiveness of channel
bonding and packet priority.
There are no ill effects from too-large receive rings. */
#define TX_RING_SIZE 16
#define TX_QUEUE_LEN 10 /* Limit ring entries actually used. */
#define RX_RING_SIZE 64
/* Operational parameters that usually are not changed. */
/* Time in jiffies before concluding the transmitter is hung. */
#define TX_TIMEOUT (2*HZ)
#define PKT_BUF_SZ 1536 /* Size of each temporary Rx buffer.*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/dma-mapping.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/crc32.h>
#include <linux/bitops.h>
#include <asm/processor.h> /* Processor type for cache alignment. */
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <linux/dmi.h>
/* These identify the driver base version and may not be removed. */
static char version[] __devinitdata =
KERN_INFO DRV_NAME ".c:v1.10-LK" DRV_VERSION " " DRV_RELDATE " Written by Donald Becker\n";
/* This driver was written to use PCI memory space. Some early versions
of the Rhine may only work correctly with I/O space accesses. */
#ifdef CONFIG_VIA_RHINE_MMIO
#define USE_MMIO
#else
#endif
MODULE_AUTHOR("Donald Becker <becker@scyld.com>");
MODULE_DESCRIPTION("VIA Rhine PCI Fast Ethernet driver");
MODULE_LICENSE("GPL");
module_param(max_interrupt_work, int, 0);
module_param(debug, int, 0);
module_param(rx_copybreak, int, 0);
module_param(avoid_D3, bool, 0);
MODULE_PARM_DESC(max_interrupt_work, "VIA Rhine maximum events handled per interrupt");
MODULE_PARM_DESC(debug, "VIA Rhine debug level (0-7)");
MODULE_PARM_DESC(rx_copybreak, "VIA Rhine copy breakpoint for copy-only-tiny-frames");
MODULE_PARM_DESC(avoid_D3, "Avoid power state D3 (work-around for broken BIOSes)");
/*
Theory of Operation
I. Board Compatibility
This driver is designed for the VIA 86c100A Rhine-II PCI Fast Ethernet
controller.
II. Board-specific settings
Boards with this chip are functional only in a bus-master PCI slot.
Many operational settings are loaded from the EEPROM to the Config word at
offset 0x78. For most of these settings, this driver assumes that they are
correct.
If this driver is compiled to use PCI memory space operations the EEPROM
must be configured to enable memory ops.
III. Driver operation
IIIa. Ring buffers
This driver uses two statically allocated fixed-size descriptor lists
formed into rings by a branch from the final descriptor to the beginning of
the list. The ring sizes are set at compile time by RX/TX_RING_SIZE.
IIIb/c. Transmit/Receive Structure
This driver attempts to use a zero-copy receive and transmit scheme.
Alas, all data buffers are required to start on a 32 bit boundary, so
the driver must often copy transmit packets into bounce buffers.
The driver allocates full frame size skbuffs for the Rx ring buffers at
open() time and passes the skb->data field to the chip as receive data
buffers. When an incoming frame is less than RX_COPYBREAK bytes long,
a fresh skbuff is allocated and the frame is copied to the new skbuff.
When the incoming frame is larger, the skbuff is passed directly up the
protocol stack. Buffers consumed this way are replaced by newly allocated
skbuffs in the last phase of rhine_rx().
The RX_COPYBREAK value is chosen to trade-off the memory wasted by
using a full-sized skbuff for small frames vs. the copying costs of larger
frames. New boards are typically used in generously configured machines
and the underfilled buffers have negligible impact compared to the benefit of
a single allocation size, so the default value of zero results in never